Press transfer apparatus

Abstract

A multi-station press is provided with a press transfer device that engages articles at the press stations after processing and transfers the articles to the next station before the press performs its next press cycle. The press transfer device includes a pair of elongated transfer bars extending along the transfer directions of the press, and grippers or other article engaging elements mounted along the transfer bars to engage the articles for transfer. The transfer bars are moved together by a grip moving unit to engage the articles, the transfer bars are lifted by a lifter, the transfer bars are then moved endwise by an endwise moving unit to the next press station. The lifter then lowers the bars and the grip moving unit moves the bars apart to disengage the articles, thereby leaving the articles at the next station. The grip moving unit ensures that the transfer bars are moved far enough apart so as not to interfere with the press during the next press cycle.

We claim: 
     
       1. A press transfer mechanism for use on a multi-station press, comprising: first and second elongated transfer bars extending generally parallel to a transfer line of the multi-station press;   transfer means for moving said first and second elongated transfer bars in endwise directions;   engaging means for moving said first and second elongated transfer bars alternately together and apart in a direction generally transverse to their length;   lift means for alternately lifting and lowering said first and second elongated transfer bars, said lift means comprising: a first member mounted generally stationary relative to said multi-station press;   a second member having a first part adjacent said first member and a second part spaced from said first member to define a space;   a horizontal bearing between said first member and said first part of said second member to enable said second member to be moved generally horizontally in a direction transverse to the transfer line of the multi-station press;   a third member disposed in said space between said first member and said second part of said second member, said third member being connected to said first and second elongated transfer bars;   a vertical bearing between said first member and said third member to enable said third member to move generally vertically relative to said first member;   an angled bearing between said third member and said second part of said second member; and     means for moving said second member in a horizontal direction relative to said first member so that said third member is caused to move in a vertical direction relative to said first member by action of said angled bearing.   
     
     
       2. A press transfer device as claimed in claim 1, wherein said first and second and third bearings are linear bearings. 
     
     
       3. A press transfer device as claimed in claim 1, wherein said engaging means is mounted on said third member between said third member and said first and second elongated transfer bars so that said engaging means is alternately lifted and lowered along with said first and second elongated transfer bars. 
     
     
       4. A press transfer device as claimed in claim 1, wherein said lifting means is a first lifting means adjacent a first end of said first and second elongated transfer bars, and further comprising: a second lifting means generally identical to said first lifting means adjacent a second end of said first and second elongated transfer bars.   
     
     
       5. A press transfer device as claimed in claim 1, further comprising: numeric controlled means connected to said engaging means and said transfer means and said lifting means to coordinate movements to cause an article at a station of said multi-station press to be engaged, lifted, transferred, lowered and disengaged so as to move the article to a next station of said multi-station press.   
     
     
       6. A press transfer device as claimed in claim 5, wherein said numeric controlled means is connected to said multi-station press to coordinate movements of said transfer device with cycles of said press. 
     
     
       7. A lift means for a press transfer system, comprising: a stationary plate disposed extending in a vertical direction;   a first linear bearing mounted on a first side of said stationary plate in a horizontal direction;   a second linear bearing mounted on said first side of said stationary plate in a vertical direction;   a horizontally movable plate mounted to said first linear bearing for horizontal movement, said horizontally movable plate having a portion opposite said stationary plate at said second linear bearing and defining a space therebetween;   horizontal drive means for moving said horizontally movable plate in the horizontal direction;   a third linear bearing mounted on said horizontally movable plate at an angle between horizontal and vertical on said portion opposite said stationary plate; and   a vertically movable plate disposed in said space between said stationary plate and said horizontally movable plate, said vertically movable plate being mounted to said second linear bearing at a first side and to said third linear bearing at a second side.   
     
     
       8. A lifting means as claimed in claim 7, wherein said third linear bearing is mounted at an angle of approximately 26 degrees from horizontal. 
     
     
       9. A lifting means as claimed in claim 7, further comprising: a grip moving means mounted at least partially on said vertically movable plate;   a pair of gripper bars movable toward and away from one another by said grip moving means, said gripper bars extending along a transfer direction of a press.   
     
     
       10. A lifting means as claimed in claim 7, further comprising: grippers; transverse moving means for moving said gripper, said transverse moving means including: a gripper drive motor;   a lead screw connected to said gripper drive motor, said lead screw having right-hand threads on one portion and left-hand threads on another portion;   a first screw follower on said right-hand thread portion and a second screw follower on said left-hand thread portion;   a first cam roller connected to said first screw follower and a second cam roller connected to said second screw follower; and   a first cam engaged by said first cam roller and a second cam engaged by said second cam roller, said first cam being connected to a first of said grippers and a second cam being connected to a second of said grippers so that operation of said gripper drive motor in a first direction moves said grippers toward one another and operation of said gripper drive motor in a second direction moves said grippers away from one another.